Computer Programming Contest Preparation

    1 4
    2 1 2
    3 1 3
    4 1 4
    5 0
    6 0
    7 
    8 1 2 3 4
    9 1 x 1 2 0
   10 2 0 x 1 2
   11 3 0 0 x 1
   12 4 0 0 0 x
   13